Multiple wheel grinding machine



March 9, 1943. H. N. ROCKS ET Al 2,313,482 7 MULTIPLE WHEEL GRINDINGMACHINE Fi led June a, 1940 '7 Sheets-Sheet 1 Zslwcntors HUGH u. BocKsM/LBUBN n. HOLLENQREEN HAROLD EBALSIGEE 62 (itto rncg H. N. ROCKS ET AL2,313,482

MULTIPLE WHEEL GRINDING MACHINE March 9, 1943.

Filed June 6, 1940 .7 Sheets-Sheet 2 March-9, 1943. H. N. ROCKS ET ALMULTIPLE WHEEL GRINDING MACHINE 7 Sheets-Sheet 5 Juventprs Huqu N- ae/(s MILBUBN A-HOLLENGIEEEN HAROLD E. .BflI-SIGER March 9, 1943..

Filed June 6, 1940 '7 Sheets-Sheet 5- m J m m a m m G IQ 1| T LG 5 Ymh mas .NE NW n L fim Hm \2 N64 MNx N4 March 9, 1943.

H. N. ROCKS ET AL MULTIPLE WHEEL GRINDING MACHINE Filed June 6, 1940 '7Sheets-Sheet Inventors HUGIH N- ROCKS MILBURN A- MQLLENQR'EEN HAROLDE..BAL8IGE2 March 9, 1943.- H. N. ROCKS ET AL I 2,313,482

MULT IPLE WHEEL GRINDING MACHINE 4 Filed June 6, 1940 7 Sheets-Sheet '7Inventors HUGH N. zocxs 5 MILBURN A. HOLLENGEEEN (Ittmeg Patented Mar.9, 1943 MULTIPLE WHEEL GRINDING MACHINE Hugh N. Rocks, Milburn A.Hollengreen, and Harold E. Balsiger, Waynesboro, Pa., assignors toLandis Tool Company, Waynesboro, Pa.

Application June 6, 1940, Serial No. 339,192

24 Claims.

Our invention relates to metal working machines, particularly grindingmachines of the type having a plurality of wheels on a spindle forgrinding a plurality of axially aligned bearing surfaces simultaneously.

It is an object of our invention to provide a machine wherein the cycleof operations after loading is performed automatically.

A further object is to provide a loading mechanism for a machine of thistype.

A further object is to provide means responsive to movement of saidloading means for iniitating a predetermined cycle of operations.

A further object is to provide a machine wherein each operation in acycle is initiated in response to a previous operation.

Our invention resides in the mechanisms for efiecting sequentialoperation of the various elements of the machine. The work piece isplaced on a loading device which in turn is shifted to place the work inalignment with the head and footstock centers. Movement of the loadingdevice into this position operates a switch which causes the footstockcenter to move axially to pick up the work and to shift same intooperative engagement with the headstock center. At a predetermined pointin this movement of the footstock a locating member is moved intoposition adjacent a flange on the work piece. In response to movement ofsaid locator the work carriage is shifted to the right to cause saidflange to approach said locator. When the work has been properlypositioned the carriage stops, the locator is withdrawn, the grindingwheel is advanced toward the work, and the work rest is also moved intocontact with the work. Movement of the work rest may occursimultaneously with advance of the wheel, or it may be delayed untilafter the wheel has started to grind depending upon the characteristicsof the work to be ground, or it may be initiated manually at any time.The grinding operation may be controlled by any suitable sizing deviceor timing mechanism. When the work has been ground to size, the wheelbase is withdrawn and the withdrawal movement is utilized to efiectwithdrawal of the footstock center. The work piece thus released islifted out of grinding position by the spring actuated loader. When theloader releases the normally closed switch which actuated the footstock,a solenoid valve is shifted which moves the carriage to the left, whereit remains until another work piece is placed in position, when theabove described cycle is repeated. Withdrawal of the footstock centerand movement of the carriage to the left may be initiatedsimultaneously, also.

Figure l is an end elevation.

Figure 2 is a plan view.

Figure 3 is a sectional end view on line 3-3 of Figure 4 of the loadingmechanism.

Figure 4 is a plan view of the loading mechanism.

Figure 5 is a plan view of the footstock partly in section.

Figure 6 is a partial plan view of the footstock.

Figure 7 is an end view of the locating device.

Figure 8 is a front elevation of said device.

Figure 9 is a front elevation of the locating device showing itsrelation to a work piece.

Figure 10 is a diagram of the hydraulic system.

Figure 11 is a wiring diagram.

In the drawings, numeral It] indicates the bed of a grinding machine, Ha work carriage slidably mounted thereon, [2 a swivel table on saidcarriage, I3 a footstock on said swivel table, and M a headstock, alsoon said swivel table. A work piece [5, in this case a crankshaft, isrotatably supported on headstock center 16 and footstock center ll.Rotation of said crank is effected by a motor 18 driving the headstockspindle (not shown) thru suitable gearing or belt connections. A steadyrest 19 supports the work against the action of the grinding wheel. Alongitudinal movement of carriage H is effected by a hydraulic motorconsisting of a cylinder 20 secured to the bed and a piston slidablymounted in said cylinder. A piston rod 22 on said piston is secured to abracket 23 on carriage ll. Said movement may be efiected manually byhandwheel 24 thru any suitable transmission. A wheel base is slidablymounted onbed IE) for transverse movement toward and from said workpiece. A spindle (not shown) rotatably mounted in spaced bearings onsaid support carries one or more grinding wheels 31. A wheel dressingmechanism 32 is mounted on said support 30 behind said wheels. Thismechanism is described in detail in co-pending application Serial No.220,776 filed July 22, 1938. The mechanism for effecting said transversemovement is shown here only in diagrammatic form but is shown anddescribed fully in co-pending application Serial No. 196,254 filed March16, 1938, now Patent No. 2,211,530, granted August 13, 1940.

Loading mechanism The mechanism for placing the work in grindingposition consists of a pair of end members 40 and 4| which form a baseor support for the mechanism. A shaft 42 is rotatably mounted in saidmembers near the bottom thereof. Said shaft forms a pivoted support fora pair of arms 43 and 44 secured at opposite ends thereof. A secondshaft 45 joins said arms at another point. A pair of springs 43 and 41are attached at one end to shaft 45 and at the other end thru links 48and 49 to end members 40 and 4i respectively. Said springs serve to holdarms 43 and 44 in the position indicated at A.

A pair of arms 58 and 5| are secured to shaft 45. Said arms are urged ina counter-clockwise direction by springs 52 and 53 attached to one endof said arms. The other end of each of said arms is shaped to receive awork piece. A downwardly projecting portion of arm 5| engages anadjustable stop 54 in end member M which determines the extent ofmovement of the arms 50 and 5| toward the work supporting centers I6 andI7. Movement of arm 43 is limited by the adjustable stop 60 engaging lug52 in the end member 4I. Similar elements, not shown, limit the movementof arm 44.

A dog 05 on arm 5I serves upon movement of the loader to place a workpiece in grinding position to depress an arm 64 on shaft 6?. At theother end of said shaft is a second arm 68 adapted for operativeengagement with a limit switch 68. The function of said switch is toinitiate operation of the footstock to pick up the work piece and shiftit against the headstock center. A red I supported in said end members40 and 4i has a disk II mounted at the headstock end. A spring I3 onsaid rod urges said disk against nuts I4 on said rod. Said disk is sopositioned that if moved far enough axially it will engage a flange onthe Work piece and shift said piece off the headstock center. A meansfor so shifting said disk consists of the bracket I attached to saidfootstock center and extending into operative relation with said rod.Said bracket is movable relative to said rod but the movement is limitedby adjusting nuts I6.

Footstoclc The footstock I 3 is of conventional construction consistingof a sliding sleeve 80 in one end of which is inserted a center I! andin the other end of which is adjustably mounted a piston rod BI. Piston82 is mounted in a cylinder 83. A cap 84 on said cylinder retains aspring 85 which urges said piston and footstock center to the left. Saidpiston is shifted to the right by fluid under pressure from a valve 06shown diagrammatically in Figure 10. Said valve may be actuated in onedirection by a spring 81 and in the opposite direction by a solenoid B3.

Attached to cylinder 33 is astart and stop valve 90. A valve stem 9!passes thru one end of a bracket 92 which may be adjusted thereon bynuts 93. The other end of said bracket is attached to rod 94 slidablymounted in the foot stock base I3. Said rod may be shifted to the leftby means of a lever 95. Said rod might also be shifted automatically inresponse to the operation of the wheel base or some other suitablemechanism. However, the function of this Valve is to initiate operationof a steady rest, to be described later. As the time for starting suchan operation differs considerably from piece to piece, it is preferredto leave the control to the judgment of the operator. Means for shiftingsaid valve in the opposite direction to withdraw the back rest consistsof a fluid line 95 from the left end of cylinder 33 to the left end ofsaid valve 90.

A switch I03 mounted on said footstock is adapted to be actuated bymovement thereof. The means for actuating said switch consists of an armI pivoted to one end of a shaft WI and having one end in contact withtailrod I02 on piston 82. Said shaft is mounted in a protruding portionE24 of a member I 25 forming part of cylinder 33. A lug its on saidportion has at tached thereto one end of a spring I 01. The other end ofsaid spring is attached to arm I00 and serves to hold said arm incontact with tailrod I02 as described above.

On the other end of shaft IfiI is secured an arm H6. A cam III at oneend of said arm is pivotally supported thereon. Rotation of said cam ina counter-clockwise direction is limited by a positive stop (not shown),and in a clockwise direction it is limited yieldingly by a spring I I2.The function of said arm is to actuate said limit switch I03 in timedrelation with the movement of the footstock. The limit switch in turncontrols a work locating device.

LOCIZtOT A device for effecting longitudinal location of the work andwheel consists of a locating feeler I25 disposed in the path of travelof a flange or other portion of the work. Said locating feeler ispivctally supported on a member I2! which is in turn carried by twoparallel arms I22 and I23 pivotally attached to a bracket I24 on wheelfender I25. Another arm I26 is attached to arm I23, and also to a pistonrod I21. A piston I28 on said rod is slidably mounted in a cylinder I29.Said cylinder is in turn mounted on said fender I25. A two pole switchI38 is mounted on said fender in such a position as to be actuated bymovement of arm I26. Said member I2I supports a dial indicator I3I and alimit switch I32. Said indicator and switch are actuated by arms I33 andIE4 respectively on locating feeler I20. Said locating feeler isyieldingly held against counter-clockwise movement by a spring I35,-oneend of which rests against arm I33, the other against a portion of a lugI30 on member I2I. Clockwise movement due to said sprin is positivelylimited by a stop screw in lug I30 and disposed in the path of anotherlug I3! on locating feeler I25.

Feed mechanism The structure of the feed mechanism used on our machineis described in co-pending application Serial No. 196,254 filed March16, 1938, now Patent No. 2,211,530, granted August 13, 1940. Briefly itconsists of a piston I40 and a, cylinder I4l for shifting a feed screwand nut (not shown), aligned with the wheel support 30 toward and fromworking position. As the piston I40 moves the wheel support 30 towardworking position the exhaust fluid from cylinder I4I may pass freelythru a normally open solenoid actuated valve I42, or if said valve isclosed it must pass thru a throttle valve I43. The function of thethrottle valve is to slow down the rapid feed movement suificiently togrind surfaces such as shoulders, crankcheeks, etc. The solenoid I 44which actuates said valve is energized by a switch I45. Said switch maybe held in inoperative position by some portion of the wheel support 30or the mechanism for moving said support, in this case a tailrod I46 onthe piston I40. Said switch may be adjusted in any suitable 'towardworking position.

manner to function at any desired predetermined time during the rapidfeed movement. A pressure switch I41 is connected into the line thruwhich fluid is directed to move the support 30 A second piston I50 is acylinder II acts thru a rack and pinion or an equivalent mechanism (notshown) to rotate the feed screw or nut and thus efiect a slow feedmovement of said wheel support. Fluid under pressure for actuating saidpiston during a grinding operation is controlled by solenoid valve I55.Said valve is actuated in one d rection by a solenoid I56 and in theopposite direction by spring I51. Solenoid I56 is energized by switchI58. Said switch is actuated by the tailrod I46. The relative positionof sa d switches is such that switch I45 is released first and just asthe wheel approaches the peripheral surface to be ground, switch I58 isreleased to start the grinding feed. Fluid under pressure for moving thepiston I 40 in either direction and for resettin piston I50 iscontrolled by a reversing valve I60. Said valve may be actuated in onedirection by a spring IEI and in the opposite direction by a solenoidI62.

Steady rest operating mechanism Steady rest I9 is similar to that shownand described in co-pending application Serial No. 274,439 filed May 18,1939. ference is in the mechanism for efiecting intermittent rotation ofthe adjusting screws. Said mechanism, shown diagrammatically in Figure10, consists of a valve body I in which are slidably mounted twohydraulically interlocked reversing valves HI and I12, one of whichdirects fluid under pressure intermittently to two hydraulic motors I13and I14. Said motors are attached to the adjusting screws of steady restI9. For the sake of convenience, start and stop valve 90 shown anddescribed in connection with the footstock mechanism of Figure 5, isshown in Figure 10 as being mounted in valve body I10. Valve 90 has apassage 91 formed therein joining spaced radial passages 98 and 99. Saidpassages open into chambers I08 and I09 respectively. Fluid underpressure enters valve 99 thru chamber I09 and is directed by passages 99and 01 to passage I80 in valve body I10 leading to valve I1I. Saidpassage I80 continues as thru valve I1I to supply fluid to valve I12. Apair of passages I8I and I82 lead from passage I00 to the ends of valveI12. Relief valves I83 and I84 in each of said passages determine thepressure in each passage independently. Valve I1I directs fluid frompassage I80 thru one or the other of passages I85 or I85 to oppositeends of valve I12 to reciprocate said valve. Fluid supplied to valve I12thru passage I80 is directed thru one or the other of passages I81 orI88 to opposite ends of valve I1I to reciprocate same. A throttle valveI89 in passage I08 determines the rate of movement of valve I H and thusthe frequency of reciprocation of valve I12. Fluid supplied to valve I12thru passages ISI and I82 is directed alternately thru passages I00 andISI to fluid motors I13 and I14. Exhaust passages I92 and I93 haveconnections to each of the valves 90, HI and I12 for carrying on anyexhaust fluid passing thru said valves. For resetting the steady rest,fluid under pressure is directed by valve 90 thru passage I15 whichdivides to carry fluid to both of the motors I13 and I14. Said motorsare thus actuated in a The principal difpump motor 228.

direction to return the work engaging members to inoperative position.

Size control mechanism Size control may be efiected either bycontrolling the duration of the grinding operation or by the use of acaliper to indicate a change in size of a work piece.

The caliper type of size control is shown in 00-. pending applicationSerial No. 196,254 filed March 16, 1938, now Patent No. 2,211,530,granted August 13, 1940. In this application we make use of aconventional time control mechanism, which consists of a two polenormally closed relay 200, a cam 20I for actuating said relay, a motor202 for driving said cam, a clutch 203 for connecting and disconnectingsaid cam and motor, and a solenoid 204 for actuating said clutch.

The motor 202 may be connected as soon as the rapid feed starts but theactuation of the clutch 203 is preferably delayed until the grindingfeed begins and is therefore connected into the circuit with solenoidI50 and. switch I58.

Operation To start our machine, the operator closes start switch 2I0which connects line I thru stop switch 2 with a series of thermaloverload relays 2I2, one for each of a plurality of electric motors, andwith a relay 220 to start pump motor 22I for driving the pump whichsupplies lubricant to the spindle for rotatably supporting the grindingwheels 3I.

When sufiicient pressure has been built up in the spindle lubricatingsystem. pressure switch 222 completes a circuit from contact 223 ofrelay 220 to energize relay 225. Said relay 225 starts wheel motor 220,oil pump motor 221, and coolant Fluid under pressure for actuating thevarious mechanisms is supplied by a pump 229 thru a main conduit 231,and a number of branch conduits 231a, 2311), etc. A check valve 238prevents a return of fluid thru pump 229 when said pump is stopped. Arelief valve 239 described in detail in co-pending application SerialNo. 321,310 filed February 28, 1940, compensates for variation inviscosity of the fluid. A throttle valve 244 in line 231 determines thepressure of fluid delivered to the hydraulic system.

Headstock motor I8 may be started manually by a jog switch 230 whichcompletes a circuit from line i thru line 23I bypassing normally openpressure switch I41, thru line 232, normally closed 4 contact 233 ofrelay 234 to motor control relay 235, and then thru line 236 to line 3.The only result of closing switch 230 is to start the motor.

A work piece I5 is placed on arms 50 and 5| in a portion thereof formedto receive same. Said arms are then swung into alignment with-thecenters I6 and I1. This movement is limited by stop 54 which locates arm5|. As arm 5I engages stop 54 a dog 65 actuates arm 55 to releasenormally closed switch 68. Releasing said switch closes a circuitbetween lines 240 and 24I but the circuit is open to line I at thenormally open contact 242 of relay 243. Releasing switch 68 opens acircuit thru the normally open contacts thereof between line I and thefootstock solenoid 88 thus deenergizing said solenoid. Spring 81 thenshifts valve 85 to connect fluid line 250 with exhaust line 260 thuspermitting the escape of fluid from footstock cylinder 83. Spring 05then shifts piston 02 and center I1 to the left to engage work piece I5.As footstock center I1 moves to the left, tailrod I02 releases arm I00,and spring I01 causes said arm along with shaft II, arm I I0, and camIII to move in a counter-clockwise position to actuate normally openlimit switch I03. The time of actuation of said switch relative to thefootstock movement may be adjusted by adjusting the position of arm I onshaft III! or any other suitable arrangement. We prefer to actuate saidswitch slightly before the end of the footstock movement which shiftsthe crank I5 onto headstock center I5. Closing switch I03 completes acircuit thru normally closed contact 255 of relay 255 to energizelocator solenoid 23!. Said solenoid shifts valve 262 against spring 263to direct fluid under pressure from line 231 thru line 254 to cylinderI29 to shift piston I 28 and locating feeler I into operative positionrelative to a portion of work piece I5. Solenoid 26I may be energizedalso by manually operated two-pole switch 255 in parallel with switchI03. The poles of said switch are opened and closed alternately. Inresponse to movement of piston I28, arm I26 shown as a cam in Fig. 10,actuates normally open switch I which completes a circuit from line Ithru the normally closed pole of switch I32 to energize solenoid 2T0.Said solenoid shifts a reversing valve 21! to the left against spring212 to direct fluid from line 23'Ic thru line 273 to the left end ofcylinder 20 to shift piston 2I and carriage II to the right. Anothersolenoid 216 when energized shifts said valve to the right againstspring 211 to direct "fluid under pressure thru line 218 to the rightend of cylinder 23. The operation of said solenoid 2'15 will bedescribed later. After the actuation of solenoid 2T0, carriage II movesto the right until a portion of work piece I5 engages locating feelerI20 and shifts it far enough to actuate switch I32. Said switch thusactuated opens the circuit from line I thru normally open contact ofswitch I30 to deenergize solenoid 210, releasing valve 21! which isshifted to central position by spring 2112 to stop carriage I I withwork piece I5 in proper location relative to grinding wheels 3|.Actuation of switch I32 also closes a circuit thru the normally opencontacts thereof. This circuit connects line I thru switch I32 andswitch 255, thru normally closed timer relay contact 200 to start timermotor 202. The time cycle however does not begin until later when theclutch solenoid is energized. Said circuit also energizes relay 280. Oneof the three normally open contacts 28I completes part of a circuit thrurapid feed solenoid I52. The rest of the circuit is completed uponwithdrawal of gauge I20 when cam I 26 releases switch I30 to close thenormally closed contact thereof. Another contact 2S2 completes a circuitto energize relay 256. The circuit to locator solenoid 25I thru thenormally closed contact 255 of relay 255 is opened and the relay is heldthru the normally open contact 25!. Deenergizing solenoid 26I permitsspring 203 to shift valve 262 to direct fluid thru line 265 to shiftpiston I28 and locating feeler I20 to inoperative position. The thirdnormally open contact 283 of relay 280 provides a holding circuit thrutimer contact 205 and footstock switch I03 after the locating feeler hasbeen returned to inoperative position.

Rapid feed solenoid I62, when energized, shifts valve IEO to the leftdirecting fluid under pressure from line 231 thru line 290 to the rodend of cylinder I-II to shift piston I and wheel base 30 rapidly towardgrinding position. Exhaust fluid from the other end of said cylinder maybe directed thru a normally open bypass valve I42 from which it isdirected thru line 29I to valve I 50 .and then thru passage 292 andexhaust manifold 293 to exhaust line 260. Fluid under pressure in line290 enters cylinder 300 in which a piston 30! is slidably mounted andshifts said piston against spring 302 to close switch I47. Closingswitch I41 has the same effect as closing the normally open contacts ofswitch 230 as described above. However, in addition to starting theheadstock motor I8, relay 2-35 thru normally open contact 305 energizesrelay 3I0. Said relay is held thru its normally open contact 3| I. Inthe line between line II and said contact is a plugging or brake switch3I2. Energizing relay 3I0 closes the normally open contact 3 I 3 thereofwhich completes a circuit thru relay 243. Said circuit is held thrunormally open contact 242 of aid relay, line 240, loader switch 50 andline 24I. A normally closed contact 3l4 of relay 3I0 is opened at thistime. Said contact 3l4 is in a circuit parallel to that which includesthe normally closed contact of loader switch 50.

As piston I40 and wheel base 30 move rapidly toward the work, switch I45is released to energize solenoid I44 which shifts valve I42 to preventthe exhaust of fluid therethru from cylinder I4I. Said exhaust fluidmust then escape thru throttle valve I43 which is set fora feed ratesuitable for grinding crank checks or shoulders. As the wheel approachesthe peripheral surface to be ground, switch I58 is released,deenergizing solenoid I55 and permitting spring I51 to shift valve I55to the right. In this position, said valve directs fluid under pressurefrom line 2311) thru line I52, and throttle valve I53 to the head end ofslow feed cylinder I5I to start the grinding feed. A relief valve I54 inline I52 is set for a pressure low-er than the pressure in the systembut sufiicient for operating the slow feed mech anism. This preventsundue strain on the parts of said mechanism. Switch I58 also completes acircuit to energize clutch solenoid 204 to start the operation of thetiming mechanism, the timing motor 202 having been started at the sametime as the rapid feed.

The operator waits until he think that the portions being ground havebeen sufliciently rounded out and then shifts valve 90 to the left. Thisoperation could be included in the automatic cycle but it is preferableto leave the time for initiating same to the judgment of the operator.Fluid under pressure from line 231a enters chamber I89, radial passage95 and axial passage 9'! from which it is discharged thru radial passage98 and chamber I23 to passage I80. Fluid under pressure in passage I isdirected by valve I'Il thru either of the passages I or I86 to oppositeends of valve In to reciprocate same. Fluid in passage I80 is directedby valve II2 thru passages IS? and I88 to opposite ends of valve III toeffect reciprocation thereof. Valve I'I2 receives fluid from branchpassages I8I and I82 of passage I80. Fluid in said branches must passthru pressure reducing valves I83 and I84 each of which may be adjustedfor different pressures depending upon the requirements of thecorresponding work engaging mechanism. Fluid from said branch passagesis directed alternately by valv I12 thru passages I and I9! to back restadjusting motors H53 and I74 respectively. Said motors are thus given apulsating movement as described in the above mentioned applicationSerial No. 274,439. The frequency of said pulsations may be controlledby throttle valve I89 in passage I88 which alternately controls thesupply of fluid to and the exhaust from one end of valve Ill thuscontrolling the rate of movement of said valve and the frequency ofreciprocation of valve I12.

, At the end of the grinding period the timing contacts are opened,timer motor 262 is stopped and rapid feed relay 28B is deenergized dueto opening of tim-er contact 285 in the holding circuit of said relay.If it is desired to stop the grinding operation before the end of thegrinding cycle, relay 280 may be deenergized by opening the cycle returnswitch 268 in the circuit with the timer contact 205.

Deenergizing relay 28% opens the circuit thru contacts 282 to relay 256.However, relay 256 is kept energized by the holding circuit thrunormally open contact 25?.

The circuit thru contact 28f of relay 2% upon opening deenergizes rapidfeed solenoid :52. Spring It! then shifts valve Hi6 to the right to theposition shown in Figure 10. Fluid under pressure is directed from line237 thru line 29! and check valve 295 to cylinder i4! causing piston if!to move wheel support 38 to separate work piece 15 and wheels 3!. Fluidunder pressure in line 29i passes thru line 294 and enters the rod endof cylinder i5| to reset piston I58 and the slow feed mechanism. At thesame time switch IE8 is actuated to deenergize solenoid I58 and open thecircuit to timer motor 282. Valve E55 is then shifted to the right byspring I51 to prevent further passage of fluid under pressure from line231?) to line I52. Exhaust fluid from the other end of cylinder 55!passes thru passage I59 to valve ifiii from which it is discharged thruexhaust passage 2%, and manifold 293 to exhaust line 25a. The exhaustpassage might be dispensed with and the exhaust fluid pass out thrurelief valve 154 which is set for a much lower pressure than the rest ofthe system.

As the rearward movement of wheel base 33 continues, switch I45 isactuated to deenergize solenoid 144. spring 148 may then reset valve I42to its normal position, i. e. open to bypass exhaust fluid aroundthrottle valve I43.

Pressure switch I41 remains closed under the exhaust pressure in line298. When the rearward movement of the wheel base is completed, spring392 will shift piston SUI to open the circuit thru said switch. Relay235 will be held thru contact 343 thereof until tappet switch 394 isopened by rotation of the headstock spindle whereupon said relay will bedeenergized. Contact 305 in the circuit to relay 310 will be opened butsaid relay will be held by a circuit thru its own contact 3. Normallyclosed contact 30'! of relay 235 will complete a circuit thru saidcontact 3 to reverse relay 234. Said reverse relay, upon beingenergized, will cause motor I8 to start rotation in the oppositedirection. However, such reverse rotation immediately opens pluggingswitch 312 in the holding circuit of relay 3i0 and also deenergizesreverse relay 234 thru the normally closed contact 30'! of relay 235 tostop motor 18.

Deenergizing relay Sill opens the circuit thru contact 313 to relay 243but said relay is held by the circuit thru loader switch 68 and lines249 and 24l Line 241 is connected to line 5 thru the normally opencontact 242 of relay 243. Deenergizing said relay 3N also closes thenormally closed contact 3M which completes a circuit from line I throughcontact 242 to energize footstock solenoid 88. Said solenoid shiftsvalve 86 against spring 81 to direct fluid under pressure from line 231athru line 259 to withdraw rootstock center l1. Bracket 15 on'said centeris effective thru rod 10 and disk H to shift work piece [5 off ofheadstock center IS. The work being thus freed of the centers, thesprings 46 and 47 and 52 and 53 of the loading device will lift it outof grinding position and. carry it back to a point where the operatormay remove it and replace it with an unground piece.

At the time when footstock solenoid 88 is energized, carriage controlsolenoid 218 is also energized. Said carriage solenoid shifts valve 2|!to the right and directs fluid under pressure thru passage 218 to shiftpiston 2| and carriage II to the left to loading position.

Movement of the loading device to inoperative position permits switch 68to return to normal position as shown in Figure 11. Thus the circuitthru lines 246 and 24! is opened and relay 243 is deenergized. Withswitch 68 in normal position, footstock solenoid 88 and. carriagecontrol solenoid 276 are both energized and the valves actuated therebyare so positioned as to direct fluid under pressure to hold footstockcenter I! and carriage II in inoperative positions.

Fluid under pressure in said line 250 also passes thru line to shiftvalve 96 to the right. This movement opens passage [15 to the fluidwhich shifted said valve and said fluid is thus directed to back restmotors I13 and I74 to rotate same in a counter-clockwise direction andthus reset the work engaging members of said rest.

We claim:

1. In a metal working machine, a work support having a headstock andfootstock mounted thereon, work supporting centers in said headstock andfootstock, a loading mechanism for placing a work piece in operativeposition including a pivoted work receiving member having resilientmeans for lifting said work away from said centers, said resilient meansbeing just strong enough to overcome the weight of the work piece andhaving sufficient movement to return said work to inoperative position.

2. In a metal working machine, a support having a cutting tool mountedthereon, a work support having a headstock and a footstock mountedthereon, work supporting centers in said headstock and said footstock,mechanism for shifting one of said centers axially whereby to engage awork piece and move same into operative relation with the other center,a gauge member movable toward and from operative position fordetermining the relative axial positions of the work piece and thecutting tool, and means responsive to the shifting of said center formoving said gauge member into operative position.

3. In a metal working machine, a tool support movable toward and. from awork piece and having a cutting tool mounted thereon, a work support,means for rotatably supporting a work piece thereon, means for movingsaid work support and said tool support relatively longitudinally, meansfor relatively locating the work and tool axially including a gaugemovable toward and from work position and having means for co-actingwith a locating surface on said work piece, and means responsive tomovement of said gauge into working position for causing a relativelongitudinal movement between said tool and said work whereby toposition said tool and work for machining.

4. In a metal working machine, a tool support movable toward and from awork piece and having a cutting tool mounted thereon, a work support,means for rotatably supporting a work piece thereon, means forrelatively locating the work and tool axially including a gauge movabletoward and from working position and having means for co-acting with alocating surface on said work piece, means for causing a relativelongitudinal movement between said tool and said work, and mechanismactuated by said gauge when said tool and said work reach apredetermined position for stopping said longitudinal movement.

5. In a metal working machine, a tool support movable toward and from awork piece and having a cutting tool mounted thereon, a work support,means for rotatably supporting a work piece thereon, mechanisms foreffecting relative transverse and longitudinal movements of saidsupports, means for relatively locating the work and tool axiallyincluding a gauge movable toward and from working position and havingmeans for co-acting with a locating surface on said work piece, meansfor causing operation of said mechanism for effecting relativelongitudinal movement between said tool and said work, and mechanismsactuated by said gauge when said tool and said work reach apredetermined position for stopping said longitudinal movement and forreturning said gauge to inoperative position.

6. In a machine of the kind set forth in claim 5, means responsive tothe return of said locating gauge for actuating said transverse movingmechanism for causing a feeding movement between said tool and said workpiece.

In a machine of the kind set forth in claim 5, means responsive to thereturn of said locating gauge for actuating said transverse movingmechanism for causing a feeding movement between said tool and saidworkpiece and a size control mechanism for actuating said transversemoving mechanism to separate said work and tool at a predetermined pointin the machining operation.

8. In a metal working machine, a tool support, a cutting tool mountedthereon, means for efiecting a transverse movement of said supporttoward and from a work piece, a work support, means, for rotatablysupporting a work piece thereon, including a headstock and a footstockhaving centers for engaging a work piece, a loading mechanism forplacing a work piece in and removing same from operative position, meansfor relatively locating the work and tool axially including a gaugemovable toward and from working position and having means for actingwith a locating surface on said work piece, means responsive to movementof said gauge into working position for causing a relative longitudinalmovement between said tool and said work, mechanisms actuated by saidgauge when said tool and said work reach a predetermined longitudinalposition relative to one another for stopping said longitudinalmovement, withdrawing said gauge to inoperative position and initiatingmovement of said tool toward a work piece, a size control mechanism, andmeans actuated thereby when a work piece has reached a pred e-. terminedsize for releasing said loading mechanism to remove said work piece fromoperative position.

9. In a metal working machine, a tool support, a cutting tool mountedthereon, means for effecting a transverse movement of said supporttoward and from a work piece, a work support, means for rotatablysupporting a work piece thereon, including a headstock and a footstockhaving centers for engaging the work piece, a

loading mechanism for placing a work piece in and removing same fromoperative position, means for relatively locating the work and toolaxially including a gauge movable toward and from working position andhaving means for coacting with a locating surface on said work piece,means responsive to movement of said gauge into working position forcausing a relative longitudinal movement between said tool and saidwork, mechanisms actuated by said gauge when said tool and said workreach a predetermined longitudinal position relative to one another forstopping said longitudinal movement, withdrawing said gauge toinoperative position and initiating movement of said tool toward a workpiece, a size control mechanism, and means actuated thereby when a workpiece has reached a predetermined size for withdrawing said footstockcenter thereby releasing said loading mechanism to remove said workpiece from operative position.

10. In a metal working machine, a tool support, a cutting tool mountedthereon, means for effecting a transverse movement of said supporttoward and from a work piece, a work support, means for rotatablysupporting a work piece thereon, including a headstock and a footstockhaving centers for engaging the work piece, a loading mechanism forplacing a work piece in and removing same from operative position, meansfor relatively locating the work and tool axially including a gaugemovable toward and from working position and having means for co-actingwith a locating surface on said work piece, means responsive to movementof said gauge into working position for causing a relative longitudinalmovement between said tool and said work, mechanisms actuated by saidgauge when said tool and said work reacha predetermined longitudinalposition relative to one another for stopping said longitudinalmovement, withdrawing said gauge to inoperative position and initiatingmovement of said tool toward a work piece, a size control mechanism, andmeans actuated thereby when a work piece has reached a predeterminedsize for releasing said loading mechanism to remove said work piece fromoperative position and for returning said work support to inoperativeposition,

11. In a metal working machine, a tool support, a cutting tool mountedthereon, means for effecting a transverse movement of said supporttoward and from a work piece, a work support, means for rotatably.supporting, a work piece thereon, means for relatively locating, thework and tool axially including a gauge movable toward, and from workingposition and having means for co-acting witha. locating surface on said"work piece, means for causing a relative longitudinal movement betweensaidtool and said work to locate said parts for a cutting oper ation,and means responsive to withdrawal ofsaid gauge for initiating movementof said tool toward said work piece.

12. In, a metal working machine, a tool support,,a cutting tool; mountedthereon, means for effecting a transverse movement ofsaidsupport towardand from a work piece, a work support, means for rotatably supporting a;work piecethereon, means for relatively locating; the-work and toolaxially including, a gauge movable toward and" from working position andhaving means for co-acting with; a locating surface-onsaid work piece,means for-causi'ngarelative-longitudinalmovement-between said tool-andsaid work to locate said parts for a cutting operation, and interlockingmeans for effecting withdrawal of said gauge and for initiating movementof said tool toward said work piece.

13. In a metal working machine, a support having a cutting tool mountedthereon, a work support, means for rotating a work piece thereonincluding a headstock and footstock, an axially movable center in saidfootstock, mechanism for efiecting relative feeding and longitudinalmovements of said supports, a motor for moving said footstock centertoward and from operative position, a loading device for placing a workpiece in alignment with said footstock center, means operable when saidloading device has moved a work .piece into position for effectingoperation of said footstock center to engage said work piece and toshift same into operative relation with said headstock, means forlocating the work laterally relative to the cutting tool including agauge member, a motor operable in response to movement of said loadingmechanism for moving said gauge member into and out of operativeposition relative to a selected surface of the work piece, meansoperable after said gauge has moved into position for initiatingmovement of said work support to cause the locating surface on a workpiece to move toward said gauge, means operable when said surfacereaches a predetermined position for withdrawing said gauge and forinitiating said relative feeding movement to bring the cutting tool intooperative relation with a work piece and for actuating said workrotating means, a size control mechanism, means actuated thereby whenthe work has been ground to a pre determined size for separating saidcutting tool and work, means actuated by said separating movement forstopping rotation of the work, withdrawing said footstock center, andreturning said work support to starting position, and means operable inresponse to withdrawal of said center for causing said loading device toremove said work piece from operative position.

14. In a metal working machine, a work carriage, a tool support, acutting tool mounted thereon, mechanisms for effecting relativetransverse and longitudinal movements of said support and said carriage,mechanism for rotatably supporting a work piece on said carriage, meansfor actuating said work supporting mechanism to engage and support awork piece, a device for locating said work piece and said cutting toolaxially of one another, means whereby operation of said transverse andlongitudinal moving mechanisms, said work supporting mechanism, and saidlocating mechanism are actuated in a predetermined sequence, and meansfor initiating said sequence by placing a work piece in the machine.

15. In a metal working machine, a work carriage, a tool support, acutting tool mounted thereon, mechanisms for effecting relativetransverse and longitudinal movements of said support and said carriage,mechanism for rotatably supporting a work piece on said carriage, meansfor actuating said work supporting mechanism to engage and support awork piece, a device for locating said work piece and said cutting toolaxially of one another and in operative relation, means wherebyoperation of said transverse and longitudinal moving mechanisms, saidwork supporting mechanism, and said locating mechanism are actuated in apredetermined sequence, means for initiating said sequence by placingawork piece in the machine, a size control mechanism and means actuatedthereby for separating said work and tool, and mechanism responsive tosaid separating movement for removing said Work from the machine and forinitiating said longitudinal movement whereby to return said carriageand said tool to inoperative relation.

16. In a metal working machine, a tool support, a cutting tool mountedthereon, a work support, means for rotatably supporting a work piecethereon, mechanism for effecting a, relative transverse movement betweensaid supports at a rapid rate to position said tool and work inoperative relation, mechanism for thereafter effecting said transversemovement at a slower rate for cutting, a size control mechanismincluding a timing device, and means responsive to said transversemovement for starting said timing device and said slow transversemovement at substantially the same time whereby to determine theduration of a machining operation.

17. In a metal working machine, a support having a cutting tool mountedthereon, a work support having a headstock and a footstock mountedthereon, mechanism for effecting a relative transverse positioningmovement between said supports, work supporting centers in saidheadstock and said footstock, mechanism for shifting one of said centersaxially whereby to engage a work piece and move same into operativerelation with the other center, a gauge member movable toward and fromoperative position for determining the relative axial positions of thework piece and the cutting tool, and means for efiecting withdrawal ofsaid gauge and for initiating operation of said transverse positioningmovement. 7

18. In a metal working machine, a work support, a loading mechanism forplacing work in and removing same from operative position, resilientmeans for holding said loading mechanism in inoperative position, meansfor holding the work in operative position against the action of saidresilient means including a headstock and a footstock each having acenter for engaging and supporting the work piece, means for retractingone of said centers, said resilient means being operable upon withdrawalof said center for returning said work and loading mechanism toinoperative position.

19. In a metal working machine, a tool support movable toward and from awork piece and having a cutting tool mounted thereon, a work support,means for rotatably supporting a work piece thereon, mechanisms foreffecting relative transverse and longitudinal movements of saidsupports, means for relatively locating the work and tool axiallyincluding a gauge movable toward and from working position and havingmeans for co-acting with a locating surface on said work piece, meansfor causing operation of said mechanism for elfecting relativelongitudinal movement between said tool and said work, mechanismsactuated by said gauge when said tool and said work reach apredetermined position for stopping said longitudinal movement and forreturning said gauge to inoperative position, and mechanisms operable intimed relation with said gauge return movement for actuating saidtransverse moving mechanism.

20. In a metal working machine, a tool support movable toward and from awork piece and having a cutting tool mounted thereon, a work support,means for rotatably supporting a work piece thereon, mechanisms foreffecting relative transverse and longitudinal movements of saidsupports, means for relatively locating the work and tool axiallyincluding a gauge movable toward and from working position and havingmeans for co-acting with a locating surface on said work piece, meansfor causing operation of said mechanism for effecting relativelongitudinal movement between said tool and said Work, mechanismsactuated by said gauge when said tool and said work reach apredetermined position for stopping said longitudinal movement, forreturning said gauge to inoperative position, and for actuating saidtransverse moving mechanism to cause the tool to be moved to operativeposition.

21. In a metal working machine, a Work support having means thereon forrotatably supporting a work piece, a loading mechanism including amember movable from a remote inoperative position to a position adjacentsaid rotatable work supporting means, means for normally holding saidmember in said inoperative position, a work carrier mounted on saidmember, means for holding said work carrier in position with the workpiece out of alignment with said rotatable supporting means when saidmember is in operative position, said carrier being movable therefrom toplace said work piece in alignment with said rotatable supporting means.

22. In a metal working machine, a work support having means thereon forrotatably supporting a work piece, a loading mechanism including apivoted member movable from a remote inoperative position to a positionadjacent said rotatable work supporting means, resilient means fornormally holding said member in said inoperative position, a workcarrier pivotally mounted on said pivoted member, means for yieldinglyholding said Work carrier in position with the work piece out ofalignment with said rotatable supporting means when said pivoted memberis in operative position, said carrier being movable against saidyielding means to place said work piece in alignment with said rotatablesupporting means.

23. In a metal Working machine, a work support having a headstock andfootstock mounted thereon, work supporting centers in said head stockand footstock, a loading mechanism for placing a work piece in operativeposition including a movable Work receiving member having means capableof exerting just enough force to overcome the weight of the work piece,said Work receiving member being movable from a position for receiving awork piece to a position for engagement of said work piece by saidcenters.

24. In a metal working machine, a tool support, a cutting tool mountedthereon, a work support, means for rotatably supporting a work piecethereon, mechanism for eiTecting a relative transverse movement betweensaid supports at a rapid rate to position said tool and work inoperative relation, mechanism for thereafter effecting said transversemovement at a slower rate for cutting, a size control mechanismincluding a timing device, and means operable substantially at the endof said transverse positioning movement for starting said timingmechanism.

HUGH N. ROCKS. MILBURN A. HOLLENGREEN. HAROLD E. BALSIGER.

